Compound, polymer, pattern forming material, and manufacturing method of semiconductor device

ABSTRACT

A pattern forming material is configured to use for forming an organic film on a film to be processed, patterning the organic film, and then forming a composite film by infiltrating a metallic compound into the patterned organic film. The pattern forming material contains a polymer including a monomer unit represented by a general formula (3) described below, 
     
       
         
         
             
             
         
       
     
     where R 21  is H or CH 3 , each R 22  is a hydrocarbon group of C 2-14  where α carbon is primary carbon, secondary carbon or tertiary carbon, Q is a single bond or a hydrocarbon group of C 1-20  carbon atoms which may include an oxygen atom, a nitrogen atom, or a sulfur atom between carbon-carbon atoms of or at a bond terminal, and a halogen atom may be substituted for the hydrogen atom.

CROSS REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2019-165444, filed on Sep. 11, 2019; theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a compound, a polymer,a pattern forming material, and a manufacturing method of asemiconductor device.

BACKGROUND

In a manufacturing process of a semiconductor device, a demand for atechnique of forming a pattern having a high aspect ratio is increasing.High etch resistance is demanded for a mask pattern used for such aprocess because the mask pattern is exposed to etching gas for a longtime.

SUMMARY

The embodiment provides a compound represented by a general formula (1)described below (hereinafter, a compound (1)), a compound represented bya general formula (2) described below (hereinafter, a compound (2)), anda polymer containing at least one of monomer unit selected from amonomer unit derived from the compound (1) and a monomer unit derivedfrom the compound (2).

wherein, R⁵ is a hydrogen atom or a methyl group, each R⁶ independentlyis an ethyl group, an n-propyl group, an isopropyl group, an n-butylgroup, an isobutyl group, or an s-butyl group.

wherein, R¹¹ is a hydrogen atom or a methyl group, each R¹²independently is a methyl group, an ethyl group, an n-propyl group, anisopropyl group, an n-butyl group, an isobutyl group, an s-butyl group,or a t-butyl group.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A to FIG. 1E illustrate processes of a manufacturing method of asemiconductor device according to an embodiment.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present invention will be explained indetail with reference to the drawings. Note that the present inventionis not limited by the following embodiments. Further, components in thefollowing embodiments include the one easily assumed by those skilled inthe art or substantially the same one.

A polymer is formed by polymerization of monomers and is constituted byrepeating units derived from a monomer. In this specification, therepeating unit constituting the polymer is referred to as a monomerunit. The monomer unit is a unit derived from a monomer, and aconstituent monomer of the monomer unit means a monomer forming themonomer unit by the polymerization.

In this specification, a compound represented by a general formula (1)is also mentioned as a compound (1). A monomer unit represented by ageneral formula (3) is also mentioned as a monomer unit (3).Furthermore, a monomer unit derived from the compound (1) is alsodenoted as a monomer unit (1). Similarly, a constituent monomer of themonomer unit (3) is denoted as a monomer (3). Also in a case of acompound and a monomer unit represented by another general formula orchemical structural formula, the compound and the monomer unit aresimilarly represented by marks of the general formula or the chemicalstructural formula.

In consideration of the above-described demand, the present inventorshave found a new polymerizable compound capable of producing a polymerwhich is useful for a pattern forming material. Furthermore, the presentinventors have found that a mask pattern with high etch resistance canbe obtained by forming an organic film from the pattern forming materialcontaining the polymer of the polymerizable compound containing thecompound having a specific substructure, patterning the organic film,and then using a composite film obtained by infiltrating a metalliccompound into the organic film as the mask pattern. Infiltrating ametallic compound into an organic film is hereinafter referred as“metallization”. Concretely, the metallization can be performed bybinding a metallic compound to the organic film having the moiety towhich the metallic compound can be bonded. After bonding, the metalliccompound may be subjected to post-treatment such as oxidation, forexample. Hereinafter, a pattern forming material containing a specificpolymer according to the embodiment will be explained.

A compound (1) of the embodiment is represented by a general formula (1)described below.

In the general formula (1), R⁵ is a hydrogen atom or a methyl group,each R⁶ independently is an ethyl group, an n-propyl group, an isopropylgroup, an n-butyl group, an isobutyl group, or an s-butyl group.

In the compound (1), R⁵ is preferably a hydrogen atom in terms ofmanufacturability. In the compound (1), two of R⁶ may be the same ordifferent, but these are preferably the same in terms ofmanufacturability.

A method producing the compound (1) is not particularly limited.Concretely, the compound (1) can be synthesized from a precursor of thecompound (1) where R⁶ in the general formula (1) is a hydrogen atom by agenerally known method and substituting the hydrogen atom with an ethylgroup, an n-propyl group, an isopropyl group, an n-butyl group, anisobutyl group, or an s-butyl group.

For example, when R⁵ in the compound (1) is a hydrogen atom, theprecursor can be synthesized according to a report from Yiding Xu andothers (Macromolecules 2009, 42(7), 2542-2550). A process to obtain thecompound (1) (where R⁵ is the hydrogen atom) from the precursoraccording to the report is illustrated in a reaction path (1) describedbelow. In the reaction path (1), the precursor is represented by achemical structural formula F. In the reaction path (1), R⁶ refers thesame as R⁶ in the general formula (1).

In the reaction path (1), a compound A (5-methylbenzene-1,3-dicarboxylicacid) is set as a starting material. First, a compound B(5-methylbenzene-1,3-dicarboxylic acid dichloride) is obtained byreacting thionyl chloride with the compound A. Next, carboxylic acids ofa compound C (5-methylbenzene-1,3-dimethyl dicarboxylate) are protectedby reacting methanol with the compound Bin the presence oftriethylamine. N-bromosuccinimide (NBS) is reacted with the compound Cin a carbon tetrachloride solvent to brominate a methyl group at the 5position to obtain a benzylbromo derivative (a compound D), followed bya reaction with triphenylphosphine (PPh3) to obtain a compound E (abenzyltriphenylphosphonium bromide derivative).

A compound F (5-vinylbenzene-1,3-dicarboxylic acid) is obtained as aprecursor of the compound (1) (where R¹ is a hydrogen atom) by forming avinyl group in compound E by applying formaldehyde in the presence ofsodium hydroxide which simultaneously deprotects the protecteddicarboxylic acid by the methyl group.

The obtained 5-vinylbenzene-1,3-dicarboxylic acid was dissolved in DMF(N,N-dimethyl formaldehyde) together with N, N′-carbonyldiimidazole in asmall excess. Alcohol, represented in R⁶OH is reacted at the roomtemperature in DMF in the presence of 1.8-diazabicyclo[5.4.0]-7-undecene(DBU) to obtain 5-vinyl-1,3-bisalkyl isophthalate (the alkyl group isR⁶).

R⁶ is an ethyl group, an n-propyl group, an isopropyl group, a n-butylgroup, an isobutyl group, or an s-butyl group. In the compound (1)(where R¹ is the hydrogen atom), when R⁶ is an ethyl group,5-vinyl-1,3-bis(ethyl)isophthalate is obtained by using ethyl alcohol asthe alcohol. In the compound (1) (where R⁵ is a hydrogen atom), when R⁶is an n-propyl group, 5-vinyl-1,3-bis(n-propyl)isophthalate is obtainedby using n-propyl alcohol as the alcohol.

In the compound (1) (where R⁵ is a hydrogen atom), when R⁶ is anisopropyl group, 5-vinyl-1,3-bis(isopropyl)isophthalate is obtained byusing isopropyl alcohol as the alcohol. In the compound (1) (where R⁵ isa hydrogen atom), when R⁶ is a n-butyl group,5-vinyl-1,3-bis(n-butyl)isophthalate is obtained by using n-butylalcohol as the alcohol. In the compound (1) (where R⁵ is a hydrogenatom), when R⁶ is an isobutyl group,5-vinyl-1,3-bis(isobutyl)isophthalate is obtained by using isobutylalcohol as the alcohol. In the compound (1) (where R⁵ is a hydrogenatom), when R⁶ is a s-butyl group, 5-vinyl-1,3-bis(s-butyl)isophthalateis obtained by using s-butyl alcohol as the alcohol.

The compound (2) of the embodiment is represented by a general formula(2) described below.

In the general formula (2), R¹¹ is a hydrogen atom or a methyl group,each R¹² independently is a methyl group, an ethyl group, an n-propylgroup, an isopropyl group, an n-butyl group, an isobutyl group, ans-butyl group, or a t-butyl group.

In the compound (2), two of R¹² may be the same or different, but theseare preferably the same in terms of manufacturability.

A method producing the compound (2) is not particularly limited.Concretely, the compound (2) can be synthesized by reacting a compound I((meth)acrylic acid chloride) with a compound G(5-hydroxy-1,3-dicarboxylic acid dialkyl ester (an alkyl group is R¹²))in the presence of triethylamine by a generally known method accordingto a reaction formula (2) described below.

In the reaction formula (2), R¹¹ and R¹² refer the same as R¹¹ and R¹²in the general formula (2). Note that (meth)acrylic acid in thisspecification is a generic name of acrylic acid and methacrylic acid.Likewise, (meth)acrylate is a generic name of acrylate and methacrylate.

[Polymer]

A polymer of the embodiment is a polymer (hereinafter, it is alsomentioned as a polymer Z) containing at least one of monomer unitselected from a monomer unit derived from the compound (1) and a monomerunit derived from the compound (2).

The polymer Z may contain at least one selected from the monomer unit(1) and the monomer unit (2) among all monomer units constituting thepolymer Z. The polymer Z may be a polymer (hereinafter, called a polymerZ1) which contains the monomer unit (1) and does not contain the monomerunit (2), a polymer (hereinafter, called a polymer Z2) which containsthe monomer unit (2) and does not contain the monomer unit (1), or apolymer (hereinafter, called a polymer Z12) which contains both themonomer unit (1) and the monomer unit (2).

The polymer Z1 may contain only one kind of monomer unit (1) or two ormore kinds of monomer units (1). A content ratio of the monomer unit (1)in the polymer Z1 is preferably 50 to 100 mol %, and more preferably 90to 100 mol % with respect to all the monomer units constituting thepolymer Z1.

Similarly, the polymer Z2 may contain only one kind of monomer unit (2)or may contain two or more kinds. A content ratio of the monomer unit(2) in the polymer Z2 is preferably 50 to 100 mol %, and more preferably90 to 100 mol % with respect to all monomer units constituting thepolymer Z2.

Each of the monomer unit (1) and the monomer unit (2) contained in thepolymer Z12 may be only one kind or may be two or more kinds. A totalcontent ratio of the monomer unit (1) and the monomer unit (2) in thepolymer Z12 is preferably 50 to 100 mol %, and more preferably 90 to 100mol % with respect to all monomer units constituting the polymer Z12.

When the polymer Z contains other monomer unit than the monomer unit (1)and the monomer unit (2), the other monomer unit is not particularlylimited. Examples of the other monomer unit include, for example,styrene, methyl methacrylate, glycidyl methacrylate, methacrylic acid,acrylic acid, and so on.

The polymer can be synthesized from the constituent monomers of themonomer unit by a generally known method such as, for example, bulkpolymerization, solution polymerization, emulsion polymerization,suspension polymerization. The solution polymerization is preferred interms of redissolution to a solvent after polymerization as well aseliminating any possible impurities such as an emulsifier and water.When the polymer Z is synthesized by solution polymerization, normally,monomers are dissolved in a polymerization solvent and polymerized inthe presence of an initiator. Polymerization conditions such as anamount of the polymerization solvent, polymerization temperature, andpolymerization time are appropriately selected according to the monomer,a molecular weight of the polymer Z to be synthesized, and the like.

[Pattern Forming Material]

A pattern forming material of the embodiment (hereinafter, mentioned as“this pattern forming material”.) contains a polymer (hereinafter, alsomentioned as a polymer X.) including a monomer unit represented by ageneral formula (3) described below.

In the general formula (3), R²¹ is a hydrogen atom or a methyl group,each R²² independently is a hydrocarbon group having 2 to 14 carbonatoms where α carbon is primary carbon, secondary carbon or tertiarycarbon, Q is a single bond or a hydrocarbon group having 1 to 20 carbonatoms which may include an oxygen atom, a nitrogen atom, or a sulfuratom between carbon-carbon atoms or at a bond terminal, and a halogenatom may be substituted for the hydrogen atom.

In the monomer unit (3), two of R²² may be the same or different, butthese are preferably the same in terms of manufacturability of themonomer (3).

The monomer unit (3) has a structure having a benzene ring at a terminalof a side chain, and an ester of a carboxyl group at each of the twoposition and the five position of the benzene ring. In the ester, R²²being a group bonding to the oxygen atom next to the carbonyl group isthe hydrocarbon group having 2 to 14 carbon atoms. Further, in R²², theα carbon, that is, the carbon atom which bonds to the oxygen atom nextto the carbonyl group is a primary carbon, a secondary carbon or atertiary carbon.

The side chain as stated above in the monomer unit (3) enables to obtaina composite film where a metallic compound is firmly bonded to anorganic film that is obtained from this pattern forming material asdescribed below.

This pattern forming material is used to form an organic film on a filmthat is to be processed which is provided with a substrate (thesubstrate having the film to be processed). This pattern formingmaterial is contained in a later-described composition for patternformation of the embodiment together with, for example, an organicsolvent, and coated on the film that is to be processed by using thecomposition to form the organic film.

The organic film may be formed of this pattern forming material itselfor may be formed by the reaction of components contained by this patternforming material. After the organic film is patterned, a composite filmis formed by binding a metallic compound to the monomer unit (3) in theorganic film. Then, the composite film is used as a mask pattern, andthe above-described film that is to be processed is processed.

In the polymer X, a reaction where the metallic compound is bonded tothe monomer unit (3) is, for example, a reaction represented by areaction formula (F) or a reaction formula (G) described below. In eachof these reaction formulas, R²¹ and Q refer the same as R²¹ and Q in thegeneral formula (3), and n represents the number of repetitions of themonomer unit (3) in the polymer X.

The reaction represented by each of the reaction formula (F) and thereaction formula (G) is a reaction example of using trimethylaluminum(TMA) as the metallic compound. R²² in the monomer unit (3) isrepresented by —CR¹R²R³ (where R¹, R², and R³ each independentlyrepresent a hydrogen atom or a hydrocarbon group, wherein at least oneof these is a hydrocarbon group, and the total number of carbons is 1 to13.). In each of the reaction formula (F) and the reaction formula (G),R¹ of the monomer unit (3) is a hydrocarbon group, R² and R³ arehydrogen atoms or hydrocarbon groups, and the bonding of TMA to themonomer unit (3) is explained.

As represented by the reaction formula (F), when TMA is set to reactwith the monomer unit (3) in the polymer X, Al of TMA is coordinated toan unshared electron pair of ═O of two carbonyl groups held by themonomer unit (3). As TMA is coordinated to the unshared electron pair,bond to a primary, secondary or tertiary hydrocarbon group (—CR¹R²R³)ester-bonded to a side-chain terminal of the monomer unit (3) ispresumably weakened. The result shows that —CR¹R²R³ is cleaved from themonomer unit (3), and a monomer unit represented by a general formula(3′) where Al of TMA is bonded to each of two oxygen atoms derived fromester is formed.

The cleaved hydrocarbon group is described as R^(1′)═CR²R³ in thereaction formula (F). Here, R¹′ is a group where one hydrogen atom hasfallen off from R¹. Though a leaving group is described as R¹′═CR²R³ inthe reaction formula (F) for convenience, there can also be cases ofR¹C═R²′R³ (R²′ is a group where one hydrogen atom has fallen off fromR²) and R¹C═R³′R² (R³′ is a group where one hydrogen atom has fallen offfrom R³). Thus, a hydrogen atom comes off from the leaving group tobecome alkene, which is cleaved off. It is assumed that hydrogen whichhas come off from the leaving group is substituted to a methyl group ofTMA.

When the metallic compound is bonded to the monomer unit (3) in thepolymer X, the leaving hydrocarbon group can also be considered as thereaction represented by the following reaction formula (G) aside from aprocess of the reaction formula (F). That is, as represented by thereaction formula (G), it can be thought that the hydrocarbon group iscleaved off from the monomer unit (3) as R¹C⁺R²R³ for convenience, andis bonded to (CH₃)⁻ which is cleaved off from TMA which formsR¹C(CH₃)R²R³, and cleaved off from the main chain.

The primary, secondary or tertiary hydrocarbon group (R²²) ester-bondedto the side-chain terminal of the monomer unit (3) is cleaved under aspecific condition even in a case where the metallic compound such asTMA is not adsorbed to the carbonyl group of the monomer unit (3).However, as represented by the reaction formula (F), when the metalliccompound such as TMA is coordinated to the carbonyl group of the monomerunit (3), the cleavage of the hydrocarbon group (R²² (it is mentioned as—CR¹R²R³ in the reaction formula (F)) can be achieved under asignificantly milder condition than the above-described specificcondition. This is a new finding by the present inventors, and it can besaid that the metallization of the organic film formed by this patternforming material allows the metallic compound to be firmly bonded to theorganic film and also achieves excellent productivity.

Note that the metallization is performed with respect to the organicfilm formed by this pattern forming material in the embodiment. Theorganic film formed by this pattern forming material may be formed ofthis pattern forming material itself or may be formed by the reaction ofthe components contained in this pattern forming material as describedabove.

In this pattern forming material, the organic film formed from thepolymer X preferably has at least the structure of the side chain of themonomer unit (3) as it is. This makes it possible that the compositefilm obtained by metallizing the organic film has, for example, astructure where Al(CH₃)_(X) (where X is a number of 0 to 2 and is 2 inthe monomer unit (3′)) being the metallic compound is firmly bonded totwo oxygen atoms of the monomer unit (3′) as represented by the monomerunit (3′).

Besides, as represented by a general formula (5) described below, astructure where, for example, Al(CH₃) derived from TMA (Al(CH₃)₃) beingthe metallic compound is held by two carbonyl groups is alsoconceivable. In this case, it is considered to form firmer bonding thanthe case when Al(CH₃)₂ is held by one carbonyl group as represented bythe general formula (3′) in each of the reaction formulas (F) and (G).Note that the number of coordinated carbonyl groups depends on the kindof a metal and steric hindrance of a polymer matrix surrounding themetal. In the general formula (5), R²¹ and Q refer the same as R²¹ and Qin the general formula (3), and n represents the number of repetitionsof the monomer unit (3) in the polymer X.

In the monomer unit (3), α carbon of R²² is primary carbon, secondarycarbon, or tertiary carbon. R²² is explained using a case when R²² isrepresented by —CR¹R²R³ (where R¹, R² and R³ each independentlyrepresent a hydrogen atom or a hydrocarbon group, at least one of theseis a hydrocarbon group, and the total number of carbons is 1 to 13) asan example.

When C in —CR¹R²R³ is a primary carbon, any one of R¹, R² and R³ is ahydrocarbon group, and the remaining two are hydrogen atoms. When C in—CR¹R²R³ is a secondary carbon, any two of R¹, R² and R³ are hydrocarbongroups, and the remaining one is a hydrogen atom. When C in —CR¹R²R³ isa tertiary carbon, all of R¹, R², and R³ are hydrocarbon groups. Thetotal number of carbons of R¹, R², and R³ is 1 to 13, and the totalnumber of carbons as —CR¹R²R³ is 2 to 14.

The present inventors have verified that in a case of a monomer unitwhere the group (R²²) ester-bonded to the terminal of the side chain isCH₃ in the general formula (3), namely in a case out of a scope of theembodiment, for example, in the metallization using TMA, Al of TMA isadsorbed to the unshared electron pair of ═O of the carbonyl group, buta methyl group is difficult to be cleaved from the terminal of the sidechain. Accordingly, in such a monomer unit, it is substantiallyimpossible to have a structure of the monomer unit (3′) where Al of TMAis bonded to each of two oxygen atoms derived from ester bond.

Note that a degree of metallization in the composite film can beverified by measuring an amount of metal held by the metallic compoundin the composite film by means of X-ray photoelectron spectroscopy(XPS). The structure where the metal of the metallic compound is bondedto each of two oxygen atoms derived from ester bond which are at theterminal of the side chain of the monomer unit (3) in the organic filmcan be estimated by means of infrared spectroscopy (IR). That is, IRabsorption of carbonyl derived from ester can be detected in the organicfilm before metallization, whereas, the IR absorption is attenuatedafter the metallization, having an absorption derived from carboniumions is newly detected, thereby the metal of the metallic compound isbonded to each of the two oxygen atoms derived from ester bond of themonomer unit (3) in the organic film at the terminal of the side chain.

It is calculated that stabilization energy of Al and O in a state whereAl of TMA is coordinated to the unshared electron pair of ═O of thecarbonyl group is 15 kcal/mol. Meanwhile, in the structure where Al ofTMA is bonded to two oxygen atoms derived from ester bond in the monomerunit (3′), it can be calculated that bond energy between Aland the twooxygen atoms is 130 kcal/mol. In the monomer unit (3), α carbon of R²²,that is, C in —CR¹R²R³ representing R²² is a primary carbon, a secondarycarbon or a tertiary carbon which are in order of bond strength.

Furthermore, hydrocarbon obtained by cleavage from the terminal of theside chain of the monomer unit (3) in the event of metallization, forexample, R¹′═CR²R³ in the reaction formula (F) is preferably removedaway from the composite film. For that purpose, the total number ofcarbon atoms of R¹, R², and R³ is 1 to 13.

When the composite film obtained by using this pattern forming materialis used as an underlayer film of a later-described multilayer maskstructure, —CR¹R²R³ is cleaved from the monomer unit (3) under arelatively mild condition when C in —CR¹R²R³ is a tertiary carbon. Insuch a case when another layer is formed on the organic film as themultilayer mask structure and when C in —CR¹R²R³ is a tertiary carbon,there is a possibility that —CR¹R²R³ in the organic film is cleaved fromthe monomer unit when the layer is formed.

When —CR¹R²R³ in the monomer unit (3) is decomposed to form a carboxylicacid, the formed carboxylic acid may become an acid catalyst and when itis heated, peripheral ester bond may be further hydrolyzed. When C in—CR¹R²R³ is a primary carbon or a secondary carbon, —CR¹R²R³ is moredifficult to be cleaved compared with the case of the tertiary carbon.Therefore, C in —CR¹R²R³ is preferably a primary carbon or a secondarycarbon depending on a temperature region applied when the underlayerfilm is formed.

When the α carbon is a tertiary carbon, R²² in the monomer unit (3) is at-butyl group. When the α carbon is a secondary carbon, R²² is anisopropyl group or an s-butyl group. When the α carbon is a primarycarbon, R²² is an ethyl group, an n-propyl group, an n-butyl group, oran isobutyl group.

Concretely, when C in —CR¹R²R³ is a tertiary carbon, an example of—CR¹R²R³ includes the hydrocarbon group where R¹, R², and R³ are eachindependently, for example, a methyl group, an ethyl group, a propylgroup, a butyl group, a pentyl group, a hexyl group, a heptyl group, oran octyl group, and the total number of carbon atoms is 3 to 13. Amongthese, the t-butyl group where all of R¹, R², and R³ are the methylgroups is preferred as —CR¹R²R³.

When C in —CR¹R²R³ is a secondary carbon, an example of —CR¹R²R³includes, for example, the hydrocarbon group where when R³ is a hydrogenatom, R¹ and R² are each independently, for example, a methyl group, anethyl group, a propyl group, a butyl group, a pentyl group, a hexylgroup, a heptyl group, an octyl group, or a nonyl group, and the totalnumber of carbon atoms is 2 to 13. Among these, the isopropyl groupwhere both of R¹ and R² are methyl groups, the s-butyl group where R¹and R² are a methyl group and an ethyl group respectively, a 3-pentylgroup where R¹ and R² are both an ethyl group, a 4-heptyl group where R¹and R² are both a propyl group or a 5-nonyl group where R¹ and R² areboth an n-butyl group is preferred as —CR¹R²R³ (note that R³ is H).

When C in —CR¹R²R³ is at primary carbon, an example of —CR¹R²R³ includesthe hydrocarbon group where when R² and R³ are set as the hydrogenatoms, R¹ is, for example, a methyl group, a ethyl group, a propylgroup, a butyl group, a pentyl group, a hexyl group, a heptyl group, anoctyl group, a nonyl group, or a decyl group, and the total number ofcarbon atoms is 1 to 13. Among these, the ethyl group where R¹ is themethyl group, or the propyl group where R¹ is the ethyl group ispreferred as —CR¹R²R³ (note that R² and R³ are H). The benzyl group isalso preferred as R¹ in —CR¹R²R³ (note that R² and R³ are H).

Q in the general formula (3) is a single bond or a hydrocarbon grouphaving 1 to 20 carbon atoms which may include an oxygen atom, a nitrogenatom, or a sulfur atom between carbon-carbon atoms or at a bondterminal, and a halogen atom may also be substituted for a hydrogenatom.

Q preferably is a single bond or an ester bond. When Q is a single bond,the monomer unit (3) is a monomer unit (31) represented by a generalformula (31) described below, and when Q is an ester bond, the monomerunit (3) is a monomer unit (32) represented by a general formula (32)described below. Note that in the general formulas (31), (32), R²¹ andR²² refer the same as R²¹ and R²² in the general formula (3).

A compound where R²² is an ethyl group, an isopropyl group, or ans-butyl group among constituent monomers of the monomer unit (31) is thecompound (1) of the embodiment. A compound where R²² is an ethyl group,an isopropyl group, an s-butyl group, or a t-butyl group amongconstituent monomers of the monomer unit (32) is the compound (2) of theembodiment. When R²² is an ethyl group, an isopropyl group, or ans-butyl group in the monomer unit (3), the α carbon is a primary carbonor a secondary carbon, which is preferred in terms of the above-statedpoints.

Q in the general formula (3) is a single bond or a hydrocarbon grouphaving 1 to 20 carbon atoms which may include an oxygen atom, a nitrogenatom, or a sulfur atom between the carbon-carbon atoms or at the bondterminal, and a halogen atom may also be substituted for a hydrogenatom. Examples of the halogen atom include F, Cl, and Br. When Q is asingle bond, the monomer unit (3) is (meth)acrylate whose constituentmonomer is an ester of (meth)acrylic acid.

When Q of the monomer unit (3) is a hydrocarbon group, the hydrocarbonmay be a linear, a branched-chain, or a ring, or may be a combination ofthese. The ring may be a cycloalkyl ring or an aromatic ring, and thearomatic ring is preferred in terms of etch resistance of the obtainedcomposite film. The number of carbon atoms of Q is preferably 1 to 10when Q is not a ring, and preferably 6 to 18 when Q is a ring. When Q isa hydrocarbon group, an oxygen atom, a nitrogen atom, or a sulfur atommay be included between the carbon-carbon atoms or at the bond terminal,and a halogen atom may also be substituted for the hydrogen atom. Q ispreferably a hydrocarbon group having no heteroatom. An example of thecase when Q is a hydrocarbon group having no heteroatom includes a1,4-phenylene group, a 1,4-naphthalene group, a 1,4-anthracene group, orthe like.

The polymer X may contain one kind of monomer unit (3), or two or morekinds of monomer units (3). The polymer X may be formed of the monomerunit (3) alone or may be a copolymer of the monomer unit (3) and amonomer unit other than the monomer unit (3). A ratio of the monomerunit (3) in the polymer X is preferably 50 mol % or more, morepreferably 80 mol % or more, and further preferably 90 mol % or morewith respect to all of the monomer units of the polymer X.

The polymer X has the monomer unit (3), thereby making it possible toachieve both an excellent metallization property in the organic filmobtained from this pattern forming material containing the polymer X,and high etch resistance in the obtained mask pattern. In terms of themetallization property and etch resistance as stated above, the ratio ofthe monomer unit (3) in the polymer X is preferably 50 mol % or more,and in case when later-described properties are not considered, theratio is particularly preferably 100 mol %.

The polymer X can be synthesized from the constituent monomers of themonomer unit by a generally known method such as, for example, bulkpolymerization, solution polymerization, emulsion polymerization, orsuspension polymerization. The solution polymerization is preferred interms of redissolution to a solvent after the polymerization as well aseliminating any possible impurities such as an emulsifier and water.When the polymer X is synthesized by solution polymerization, normally,a monomer is dissolved in a polymerization solvent and polymerized inthe presence of an initiator. The monomers used for the synthesis of thepolymer X include the constituent monomers of the monomer unit (3). Aswill be described later, when the polymer X includes a monomer unitother than the monomer unit (3), constituent monomers of all the monomerunits constituting the polymer X are used in the polymerizationreaction. Polymerization conditions such as an amount of thepolymerization solvent, the polymerization temperature, and apolymerization time are appropriately selected according to the kind ofthe monomer, a molecular weight of the polymer X to be synthesized, andthe like.

A weight-average molecular weight (Mw) of the polymer X is preferably1,000 to 1,000,000 [g/mol] (hereinafter, a unit is sometimes omitted.),more preferably 2,000 to 1,000,000, and particularly preferably 2,000 to100,000. The molecular weight (Mw) of the polymer X can be measured bygel permeability chromatography (GPC).

Note that the metallic compound bonded to the organic film may bethereafter appropriately processed to be used as a mask pattern. Forexample, in a case of Al(CH₃)₃ shown in the reaction formula (F), afterthe metallic compound is bonded to the organic film, aluminum hydroxide,aluminum oxide, or the like may be formed by oxidation treatment. Theoxidation treatment is normally performed by using an oxidant such aswater, ozone, or oxygen plasma. Note that the oxidation treatment may beperformed by moisture in air without any special treatment.

Further, an explanation has been made by exemplifying Al(CH₃)₃ as themetallic compound bonded to the organic film, but an Al compound otherthan Al(CH₃)₃ is applicable, and it is possible to obtain similarbonding structures even in metallic compounds of metals other than Alsuch as, for example, Ti, V, W, Hf, Zr, Ta, and Mo.

The composite film obtained by using this pattern forming material hashigh etch resistance since the metallic compound is firmly bonded to theorganic film. Examples of etching include reactive ion etching (RIE),ion beam etching (IBE), or the like, and it is possible to achievesufficient resistance even in the IBE where particularly high resistanceis required. In order to achieve a pattern having a high aspect ratiowith respect to the film to be processed, the multilayer mask structureis sometimes applied in the mask pattern. The composite film formed byusing this pattern forming material is suitably used as the underlayerfilm to be formed between a resist film and the film to be processedwhen used for the multilayer mask structure.

Conventionally, in the multilayer mask structure targeted for high etchresistance, a carbon layer obtained by chemical vapor deposition (CVD)method has been used as the underlayer film between the resist film andthe film to be processed. On the contrary, the composite film formed bythis pattern forming material has advantages where materials thereof areinexpensive and a film is easily formed thus allowing a possiblesubstitution for the carbon deposition layer obtained by the very costlyCVD method for forming a film.

(Polymer X)

This pattern forming material contains the polymer including the monomerunit (3). In the polymer X, the monomer unit other than the monomer unit(3) may be contained within a range of not impairing the effect of theembodiment in order to impart properties (hereinafter, also mentioned as“other properties”.) required in addition to the metallization propertyand the etch resistance as a material to form the mask pattern.

An example of other properties required for the polymer X includes theproperty of making the obtained organic film insoluble to an organicsolvent. This is a particularly required property when this patternforming material is applied to the multilayer mask structure. In themultilayer mask structure, the organic film formed by using this patternforming material as described above is preferably formed as theunderlayer film between the resist film and the film to be processed. Inthis case, normally, other layers constituting the multilayer mask isformed by what is called a wet coating method; a method of coating amaterial composing the layer dissolved in an organic solvent or the likeon top of the organic film. When the organic film formed of the polymerX is soluble to the organic solvent used for the wet coating method,there is a possibility that the organic film is partly dissolved to theorganic solvent to form a mixed layer of composing materials of thelayer formed on the organic film and the organic film.

The present inventors have overcome the issue by introducing acrosslinkable monomer unit having a crosslinkable functional group at aterminal of a side chain to the polymer X in addition to the monomerunit (3), to suppress the elution of film components in the obtainedorganic film. This makes it possible that the organic film formed byusing the polymer X becomes insoluble to the organic solvent, and whenlayers on the organic film is formed by the wet coating method, themixed layer is hardly formed. Hereinafter, the polymer X having thecrosslinkable monomer unit in addition to the monomer unit (3) issometimes mentioned as a crosslinkable polymer X.

The crosslinkable functional group in the crosslinkable monomer unit isnot particularly limited as long as it functions as crosslinker, but interms of stability, a functional group that exhibits a crosslinkingfunction by applying energy from outside, for example by heating orlight irradiation, is preferred. Examples of the crosslinkablefunctional group include a glycidyl group, an oxetanyl group, an aminogroup, an azido group, a thiol group, a hydroxyl group, a carboxylgroup, or the like, and the glycidyl group, the oxetanyl group, thehydroxyl group, the carboxyl group, or the protected carboxyl group isparticularly preferred from the viewpoints where a structure aftercrosslinkage is inert to the metallic compound, as well as energyrequired for a crosslinking reaction is relatively low.

An example of a constituent monomer of the crosslinkable monomer unitincludes a monomer where a monovalent organic group having acrosslinkable functional group at a terminal is bonded to any carbonatom of an ethylene group. Concretely, an example of the crosslinkablemonomer unit includes a monomer unit (4) represented by a generalformula (4) described below.

In the general formula (4), R³⁰, R³¹, and R³² are each independently ahydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, andR³³ is a single bond or a hydrocarbon group having 1 to 20 carbon atomswhich may include an oxygen atom, a nitrogen atom, or an ester bondbetween carbon-carbon atoms or at a bond terminal, and L is acrosslinkable functional group.

As a constituent monomer of the crosslinkable monomer unit,(meth)acrylate where a compound having a crosslinkable functional groupat a terminal is ester-bonded to (meth)acrylic acid or a styrenederivative where a compound having a crosslinkable functional group at aterminal is substituted is preferred.

An example of (meth)acrylate having the glycidyl group among(meth)acrylates to be the constituent monomer of the crosslinkablemonomer unit concretely includes a compound represented by a generalformula L1 described below.

H₂C═C(R)—C(═O)—O—(R¹⁵—O)_(m)-Gly  L1

In the general formula L1, R is a hydrogen atom or a methyl group, andGly is the glycidyl group, m is 0 to 3, and R¹⁵ is an alkylene grouphaving 1 to 10 carbon atoms. An example of (meth)acrylate represented byL1 concretely includes glycidyl (meth)acrylate represented by a generalformula L1-1 described below. In each of the following general formulas,R is a hydrogen atom or a methyl group.

Concretely, an example of (meth)acrylate having the oxetanyl group among(meth)acrylates to be the constituent monomer of the crosslinkablemonomer unit includes (3-ethyl-3-oxetanyl)methyl(meth)acrylaterepresented by a general formula L2-1 described below. In the followinggeneral formula, R is a hydrogen atom or a methyl group.

Concretely, an example of the styrene derivative having the glycidylgroup among styrene derivatives to be the constituent monomer of thecrosslinkable monomer unit includes a compound represented by a generalformula L3 described below.

A copolymer of the monomer unit (3) and the crosslinkable monomer unitconstituting the polymer X preferably has randomness, and it issufficient that a combination of the monomer unit (3) and thecrosslinkable monomer unit is determined from the above viewpoint.

When the polymer X contained by this pattern forming material containsthe crosslinkable monomer unit, the polymer X may contain only one kindof crosslinkable monomer unit, or may contain two or more kinds ofcrosslinkable monomer units. When the polymer X contains one kind ofmonomer unit (3) and two or more kinds of crosslinkable monomer units,the polymer X may be a mixture of two or more kinds of copolymers eachincluding the monomer unit (3) and each of the crosslinkable monomerunits or may be one kind of copolymer including one kind of monomer unit(3) and two or more kinds of crosslinkable monomer units.

When the polymer X contains two or more kinds of monomer units (3) andone kind of crosslinkable monomer unit, the polymer X may be a mixtureof two or more kinds of copolymers each including the crosslinkablemonomer unit and each of the monomer units (3), or may be one kind ofcopolymer including two or more kinds of monomer units (3) and one kindof crosslinkable monomer unit.

When the polymer X contains the monomer unit (3) and the crosslinkablemonomer unit, the crosslinkable functional groups of the crosslinkablemonomer units included in different polymer chains react with each otherto be bonded, resulting in that the respective main chains of aplurality of polymers are crosslinked to make it difficult to dissolvethe polymer regardless of whether the polymer X is a mixture of two ormore kinds of copolymers or is constituted by one kind of copolymer asdescribed above. Note that the reaction of the crosslinkable functionalgroups is preferably performed by, for example, heating, lightirradiation, or the like after the organic film is formed.

A ratio of the crosslinkable monomer unit in the polymer X is preferably0.5 mol % or more and less than 20 mol %, more preferably 1 mol % ormore and less than 10 mol %, and further preferably 2 mol % or more andless than 10 mol % to all of the monomer units constituting the polymerX.

When the ratio of the crosslinkable monomer unit is less than 0.5 mol %to all of the monomer units, the crosslinking in the polymer X cannot besufficiently achieved allowing the polymer to dissolve into a solvent,resulting in a possibility that the component of the organic film iseluted to a wet coating solution used for forming an upper layer on theorganic film. When the ratio of the crosslinkable monomer unit is 20 mol% or more to all of the monomer units, there is a possibility that highcrosslink density causes suppression of diffusion of the metalliccompound into the organic film which prevents the organic film frommetallization deep throughout its thickness

Hereinafter, the crosslinkable polymer X will be explained byexemplifying a case where the crosslinkable monomer unit is the monomerunit L1-1. The following explanation is applied to the crosslinkablepolymer X even when the crosslinkable monomer unit is othercrosslinkable monomer units than the monomer unit L1-1.

A chemical structural formula X11 described below represents a chemicalstructural formula of the polymer X constituted by combining the monomerunit (3) and the monomer unit L1-1. The polymer represented by thechemical structural formula X11 is hereinafter mentioned as a polymerX11. Hereinafter, other polymers are also denoted similarly. In thechemical structural formula X11, R²¹, R²², and Q refer the same as R²¹,R²², and Q in the general formula (3), and R is a hydrogen atom or amethyl group.

The polymer X11 is constituted of the monomer unit (3) and the monomerunit L1-1. A molar ratio of the monomer unit L1-1 to all the monomerunits in the polymer X11 is represented by n2, and a molar ratio of themonomer unit (3) to all the monomer units in the polymer X11 isrepresented by n1. A sum of n1 and n2 is 100 mol % in the polymer X11.Note that in the polymer X11, the monomer unit (3) and the monomer unitL1-1 may be alternately present, or may be randomly present. Therespective monomer units are preferably uniformly present according tocontent ratios of the respective monomer units.

When the polymer X contained by this pattern forming material is thecrosslinkable polymer X and constituted of only the polymer X11, n2 inthe polymer X11 is preferably 0.5 mol % or more and less than 20 mol %,more preferably 1 mol % or more and less than 10 mol %, and further morepreferably 2 mol % or more and less than 10 mol % by the similar reasonto the above explanation. Besides, n1 is preferably more than 80 mol %and 99.5 mol % or less, more preferably more than 90 mol % and 99 mol %or less, and further more preferably more than 90 mol % and 98 mol % orless.

The crosslinkable polymer X may be a mixture of the polymer X11 and theother crosslinkable polymer X. When the crosslinkable polymer X is themixture of the polymer X11 and the other crosslinkable polymer X,content ratios of the monomer unit (3) and the crosslinkable monomerunit in each crosslinkable polymer does not necessarily fall within theabove-described ranges. The content ratios of the monomer unit (3) andthe crosslinkable monomer unit preferably fall within theabove-described range as the entire mixture.

Adjustment of ratios of the respective monomer units in thecrosslinkable polymer X can be performed by adjusting ratios of monomersadded at a time of polymerization. A molecular weight (Mw) of thecrosslinkable polymer X is preferably 1,000 to 100,000,000, and morepreferably 2,000 to 100,000.

Conditions when the crosslinkable polymers X are crosslinked depend onthe kind of crosslinkable functional group in by the crosslinkablemonomer unit. For example, when the crosslinkable functional group isthe glycidyl group or the oxetanyl group, the crosslinking is achievedby opening an epoxy ring or an oxetane ring. Accordingly, the polymers Xare crosslinked by heating or light irradiation under the conditionsthat the epoxy ring or the oxetane ring is opened. Note that when thecrosslinkable polymer X is crosslinked, a curing agent may be used.

The curing agent has a reactivity with the crosslinkable functionalgroup and allows the crosslinkable functional groups to be bonded toeach other by the curing agent. The curing agent promotes a crosslinkingreaction and makes the crosslinking of the polymers X easy. Accordingly,a suitable curing agent depends on the kind of the crosslinkable monomerunit. For example, when the crosslinkable functional group held by thecrosslinkable monomer unit is a glycidyl group, an amine compound, acompound having an acid anhydride structure, a compound having acarboxylic acid, or a compound having a hydroxyl group can be suitablyused as the curing agent.

The amine compound has a plurality of primary amines or secondary aminesin a structure. Examples of the amine compound usable for the curingagent include, for example, ethylenediamine, trimethylenediamine,tetramethylenediamine, pentamethylenediamine, hexamethylenediamine,heptamethylenediamine, octamethylenediamine, nonamethylenediamine,decamethylenediamine, diethylenetriamine, triethylenetetramine,tetraethylenepentamine, pentaethylenehexamine, 1,2-diaminocyclohexane,1,3-diaminocyclohexane, 1,4-diaminocyclohexane, o-phenylenediamine,m-phenylenediamine, p-phenylenediamine, m-xylenediamine,p-xylenediamine, isophorondiamine, 4,4′-methylenedianiline,diaminodiphenylsulfone, diaminodiphenyl ether, or the like.

Examples of the compound having the acid anhydride structure usable forthe curing agent include, for example, hexahydrophthalic anhydride,4-methylhexahydrophthalic anhydride, succinic anhydride, itaconicanhydride, dodecenylsuccinic anhydride, or the like.

Examples of the compound having the carboxylic acid usable for thecuring agent include, for example, hexahydrophthalic acid,4-methylhexahydrophthalic acid, succinic acid, itaconic acid,dodecenylsuccinic acid, citric acid, terephthalic acid, or the like.

The compound having a hydroxyl group includes a plurality of hydroxylgroups in a structure. Examples of the compound having a hydroxyl groupusable for the curing agent include, for example, polyphenol,1,4-benzenediol, 1,3-benzenediol, 1,2-benzenediol, ethylene glycol, orthe like.

A curing promotor having tertiary amine may be added in order to enhancethe reactivity of the curing agents other than the curing agent of theamine compound. Examples of such a curing accelerator include, forexample, cyandiamide, 1,8-diazabicyclo(5,4,0)-undecene-7,1,5-diazabicyclo(4.3.0)-nonene-5, tris(dimethylaminomethyl)phenol,ethylene glycol, or the like.

When this pattern forming material contains a curing agent together withthe crosslinkable polymer X, an amount of the curing agent is preferablyan amount where a ratio of a reactive group to the crosslinkablefunctional group in the curing agent is 0.01 to 1 mol with respect to 1mol of the crosslinkable functional group in the crosslinkable polymerX.

The polymer X contained by this pattern forming material may furtherinclude another monomer unit (hereinafter, mentioned as “an alternativemonomer unit”) other than the monomer unit (3) and the crosslinkablemonomer unit as necessary. In the polymer X, having the alternativemonomer unit makes it possible to adjust solubility of the polymer X toan organic solvent, film formability when coating a film, a glasstransition temperature of the film after coating the film, heatresistance, and the like.

Examples of a monomer constituting the alternative monomer unit include,for example, styrene, 1-vinylnaphthalene, 2-vinylnaphthalene,9-vinylanthracene, vinylbenzophenone, hydroxystyrene, methyl(meth)acrylate, (meth)acrylic acid, methyl 4-vinyl benzonate, 4-vinylbenzoic acid, a monomer represented by a general formula (6) describedbelow, or the like. The alternative monomer unit can be constituted ofat least any one of these monomers.

In the general formula (6), R⁶¹, R⁶², and R⁶³ each independentlyrepresent a hydrogen atom or a hydrocarbon group which may include anoxygen atom, at least one of these is the hydrocarbon group, the totalnumber of carbons of these is 1 to 13, and these may form a ring bybeing bonded to each other. R⁶⁴ is a hydrogen atom or a methyl group. Q¹is a single bond or a hydrocarbon group having 1 to 20 carbon atomswhich may contain an oxygen atom, a nitrogen atom, or a sulfur atombetween carbon-carbon atoms or at a bond terminal, and a halogen atommay be substituted for a hydrogen atom.

A ratio of the alternative monomer unit is preferably 50 mol % or less,more preferably 10 mol % or less, and further preferably 1 mol % or lessto all the monomer units constituting the polymer X. Setting the ratioof the alternative monomer unit to 50 mol % or less makes it possible tokeep the content of the monomer unit (3) in the organic film high, andfirmly bond a larger amount of the metallic compound in the organicfilm.

This pattern forming material may contain a component other than thepolymer X as necessary within a range of not impairing the effect ofthis embodiment in addition to the polymer X. Examples of the componentother than the polymer X typically include the above-described curingagent and curing promotor. Examples of a component other than the curingagent and the curing promotor include a thermal acid generator, aphotoacid generator, or the like. A content of the component other thanthe polymer X in this pattern forming material can be appropriatelyselected according to each of the components. For example, the contentof the curing agent is as explained above. The content of the componentexcluding the polymer X other than the curing agent is preferably 1 wt %or less, and more preferably 0.1 wt % or less to the total amount of thepattern forming material.

A method of forming the organic film by using this pattern formingmaterial may be a dry coating method or a wet coating method. When theorganic film is formed by the dry coating method, the organic film canbe formed for example, by a vapor disposition method by using thispattern forming material itself. When the organic film is formed by thewet coating method, coating a composition including this pattern formingmaterial in an organic solvent and drying on the film that is to beprocessed to form the organic film is preferred.

(Embodiment of Composition for Pattern Formation)

A composition for pattern formation (hereinafter, also simply mentionedas a “composition”.) of the embodiment is a composition where an organicfilm is formed by using a pattern forming material to be patterned on afilm to be processed of a substrate having the film to be processed, andthereafter a composite film obtained by infiltrating a metallic compoundinto the organic film is used as a mask pattern when the film that is tobe processed is processed, and which includes the pattern formingmaterial for forming the organic film, and the composition contains thepattern forming material containing the polymer including the monomerunit (3) represented by the above-described general formula (3) and theorganic solvent capable of dissolving the pattern forming material.

This pattern forming material can be used as the pattern formingmaterial in the composition of the embodiment. The composition of theembodiment can be used for a similar use to that of the one explainedabove in this pattern forming material. The organic solvent in thecomposition of the embodiment is not particularly limited as long as itis an organic solvent dissolving this pattern forming material,particularly the polymer X contained by this pattern forming material.

Examples of the organic solvent dissolving the polymer X includearomatic hydrocarbons such as toluene, xylene, and mesitylene, ketonessuch as cyclohexanone, acetone, ethyl methyl ketone, and methyl isobutylketone, or cellosolves such as methyl cellosolve, methyl cellosolveacetate, ethyl cellosolve acetate, butyl cellosolve acetate, andpropylene glycol monomethyl ether acetate (PGMEA). Among the solventsdescribed the cellosolves are preferred. The organic solvent can be usedby combining two or more kinds if necessary.

A content of the pattern forming material in the composition of theembodiment is preferably 1 to 30 wt %, more preferably 1 to 20 wt %, andfurther preferably 1 to 15 wt % to the entire composition. A content ofthe organic solvent in the composition of the embodiment is preferably70 to 99 wt %, more preferably 80 to 99 wt %, and further preferably 85to 99 wt % to the entire composition. The content of each of the patternforming material and the organic solvent in the composition of theembodiment falls within the above-described range, thereby making itpossible to form the organic film well by the wet coating method ontothe film that is to be processed.

A normal method is applicable as a method of coating the composition ofthe embodiment on the film to be processed by the wet coating method.Concretely, spin coating or dip coating is preferred. The organic filmcan be formed by removing the organic solvent from a coated film of thecomposition during drying process. When the polymer X is thecrosslinkable polymer X, crosslinking treatment is performed to causecrosslinking, for example, by heating or light irradiation, according tothe crosslinkable polymer X used at a time of organic film formation.

Here, when the organic film is formed by the composition of theembodiment, the organic film is preferably formed under a conditionwhere R²² is not cleaved from the monomer unit (3). If R²² is cleavedfrom the monomer unit (3) when the organic film is formed, there is apossibility that uniform metallization does not occur throughout thefilm thickness at the metallization procedure that is later to beperformed. It is highly likely that a firm bond between the organic filmand the metallic compound cannot be achieved.

(Embodiment of Pattern Forming Method and Manufacturing Method ofSemiconductor Device)

A pattern forming method of the embodiment has processes of (A1) to (C)described below.

(A1) a process of forming an organic film on a substrate by using apattern forming material containing a polymer including the monomer unit(3).(B) a process of patterning the organic film obtained by (A1).(C) a process of forming a composite film by infiltrating a metalliccompound into the patterned organic film to obtain a mask pattern formedof the composite film.

A manufacturing method of a semiconductor device of the embodiment hasprocesses of (A) to (D) described below.

(A) a process of forming an organic film on a film to be processed whichis provided with a substrate by using a pattern forming materialcontaining a polymer including the monomer unit (3).(B) a process of patterning the organic film obtained by (A).(C) a process of forming a composite film by infiltrating a metalliccompound into the patterned organic film to obtain a mask pattern formedof the composite film.(D) a process of processing the film that is to be processed by usingthe mask pattern.

This pattern forming material explained above is applicable as a patternforming material to be used in this pattern forming method and themanufacturing method of the semiconductor device of the embodiment.

Hereinafter, the manufacturing method of the semiconductor device of theembodiment will be explained by using FIG. 1A to FIG. 1E. Here, theprocesses of (A1), (B), and (C) in the pattern forming method of theembodiment correspond to the processes of (A), (B), and (C) in themanufacturing method of the semiconductor device of the embodiment,respectively. Accordingly, to each of the processes of (A1), (B), and(C) in the pattern forming method of the embodiment, a concrete methodof each of the processes of (A), (B), and (C) in the manufacturingmethod of the semiconductor device described below can be similarlyapplied.

FIG. 1A to FIG. 1E are cross sectional views each illustrating oneprocess of the manufacturing method of the semiconductor deviceaccording to the embodiment. In the manufacturing method of thesemiconductor device of the embodiment, the processes progress in orderof FIG. 1A to FIG. 1E.

FIG. 1A is a cross sectional view schematically illustrating the process(A), namely, the process where the organic film is formed on the film onthe substrate that is to be processed. The film on the substrate is tobe processed by the pattern forming material. In this embodiment, anorganic film 3 is formed from the pattern forming material in order toprocess a film to be processed 2 formed on a semiconductor substrate 1.

In the process (A), first, the semiconductor substrate 1 on which thefilm to be processed 2 has been formed is prepared. The film to beprocessed 2 may be a single layer film of a silicon oxide film or thelike, or may be a multilayer film composing a three-dimensional memorycell array such as a NAND-type flash memory, or the like. In an exampleillustrated in FIG. 1A, the film to be processed 2 is a multilayer filmwhere nitride films 21 and oxide films 22 are alternately layered.

Here, in the pattern forming method of the embodiment, the semiconductorsubstrate 1 may have the film to be processed 2, but the film to beprocessed 2 is not essential. Further, in the pattern forming method, asubstrate of glass, quartz, mica, or the like can be used in place ofthe semiconductor substrate 1.

This pattern forming material is coated on the film to be processed 2 ofthe semiconductor substrate 1. In a case of the dry coating method suchas vapor deposition, for example, this pattern forming material itselfis coated. In a case of the wet coating method such as spin coating ordip coating, the composition of the embodiment is coated. Next, dryingfor removal of the organic solvent, and heating or light irradiation forcrosslinking are performed if necessary to form the organic film 3 onthe film to be processed 2.

The drying is performed in the case of the wet coating method. Thecrosslinking is performed in a case where the polymer X contained bythis pattern forming material is the crosslinkable polymer X. Thecrosslinking is achieved by bonding crosslinkable functional groupsbetween different polymers to each other. When the curing agent or thelike is added, such a bond of crosslinkable functional groups isperformed through molecules of the curing agent. Heating or lightirradiation may be performed in order to promote a crosslinkingreaction.

When the crosslinking is performed upon heating, heating temperaturedepends on the kinds of the crosslinkable functional group in thecrosslinkable monomer unit and the curing agent. The heating temperatureis preferably about 120° C. or higher, more preferably 160° C. orhigher, and further preferably 200° C. or higher. Note that, asmentioned above, the heating is preferably performed at a temperaturewhere R²² is not cleaved from the monomer unit (3). Besides, the heatingis preferably performed at a temperature where decomposition of apolymer main chain is eliminated.

For example, when the α carbon of R²² in the monomer unit (3) is thetertiary carbon, the heating temperature is preferably about 250° C. orlower, and more preferably 200° C. or lower. When the α carbon of R²² isthe secondary carbon, the heating temperature is preferably about 300°C. or lower, and more preferably 250° C. or lower. When the α carbon ofR²² is the primary carbon, the heating temperature is preferably about350° C. or lower, and more preferably 300° C. or lower. Note that in acase of the wet coating method, normally, the drying, namely the removalof the organic solvent contained in the composition of the embodiment isperformed collectively by this heating. Thus, the organic film 3 formedof this pattern forming material, or obtained by crosslinking thepolymers X in this pattern forming material can be obtained.

FIG. 1B and FIG. 1C are sectional views each schematically illustratingthe process (B), namely, the process where the organic film 3 obtainedin the process (A) is patterned. The organic film 3 functions as anunderlayer of a multilayer mask structure 6 as illustrated in FIG. 1Band FIG. 1C. FIG. 1B illustrates a state where a silicon oxide film 4 isformed on the organic film 3 as a functional film that is to bepatterned and a resist pattern 5 p is formed thereon.

The silicon oxide film 4 is formed by, for example, heating a SOG (spinon glass) film formed on the organic film 3 by the following method at apredetermined temperature, for example, between 150° C. and 300° C.Similarly to the above, the heating is preferably performed at thetemperature where R²² is not cleaved from the monomer unit (3). The SOGfilm is formed by spin-coating a wet coating solution where componentsof the SOG film have been dissolved in an organic solvent on the organicfilm 3.

Although unillustrated, antireflection film may be formed on the siliconoxide film 4. The antireflection film allows precision exposure bypreventing reflection from an underlayer when a resist film which isformed by the following treatment is patterned. A material such as anovolac resin, a phenol resin, or polyhydroxystyrene can be used as theantireflection film.

Next, the resist film is formed on the silicon oxide film 4, and theresist film is formed into the resist pattern 5 p by using a lithographytechnology, an imprint technology, or the like. In the imprinttechnology, the resist pattern 5 p is formed by dropping a resist on thesilicon oxide film 4, pressing a template where a fine pattern has beenformed to the resist film, and curing the resist film by irradiationwith ultraviolet rays.

FIG. 1C is a cross sectional view illustrating a state after etching thesilicon oxide film 4 using the resist pattern 5 p as a mask, to form asilicon oxide pattern 4 p, and further etching the organic film 3 usingthe resist pattern 5 p and the silicon oxide pattern 4 p as masks, toform an organic film pattern 3 p. The etching of the silicon oxide film4 is performed by using fluorine-based gas (F-based gas), and theetching of the organic film 3 is performed by using oxygen-based gas(O₂-based gas). As illustrated in FIG. 1C, a structure where the organicfilm pattern 3 p, the silicon oxide pattern 4 p, and the resist pattern5 p are layered in this order is one example of the multilayer maskstructure 6.

When the antireflection film is formed on the silicon oxide film 4, theantireflection film is patterned before the etching of the silicon oxidefilm 4. Note that after the formation of the silicon oxide pattern 4 p,a film thickness of the resist pattern 5 p may be adjusted so that theresist pattern 5 p is simultaneously removed. Further, after theformation of the organic film pattern 3 p, a film thickness of thesilicon oxide film pattern 4 p may be adjusted so that the silicon oxidepattern 4 p is simultaneously removed.

When the organic film pattern 3 p is formed based on the multilayer maskstructure 6 as presented in this embodiment, the silicon oxide pattern 4p and the resist pattern 5 p being upper layers of the organic filmpattern 3 p may be removed before the process where the composite filmis formed by infiltrating the metallic compound into the patternedorganic film (organic film pattern 3 p) to obtain a mask pattern formedof the composite film, which is the process (C).

FIG. 1D is a cross sectional view illustrating a state after the process(C), and the organic film pattern 3 p illustrated in FIG. 1C ismetallized to become a mask pattern 3 m on the film to be processed 2 onthe semiconductor substrate 1. Note that in the process from theformation of the organic film 3 to the formation of the organic filmpattern 3 p, the condition is adjusted so that R²² in the monomer unit(3) derived from the polymer X at the terminal of the side chain is notcleaved. The metallization of the organic film pattern 3 p formed inthis manner is performed, for example, as stated below.

A multilayer body having the film to be processed 2 and the organic filmpattern 3 p on the semiconductor substrate 1 in that order is carried ina vacuum device, and the organic film pattern 3 p is exposed to gas orliquid of the metallic compound such as TMA as a metal-containing fluid.Molecules of the metallic compound are adsorbed to the carbonyl group ofthe monomer unit (3) in the polymer of the organic film pattern 3 p andR²² is cleaved as represented in the above-described reaction formula(F). Then, for example, as represented by the monomer unit (3′) in thereaction formula (F), a structure where the metallic compound(Al(CH₃)_(X)) is firmly bonded to each of two oxygen atoms of theorganic film is formed.

In order to firmly bind the metallic compound to the organic filmpattern 3 p as described above, exposure treatment of the metalliccompound to the organic film pattern 3 p is preferably performed underheating. A heating temperature is appropriately selected according to akind of the metallic compound and a kind of the monomer unit (3),particularly the kind of R²². For example, when the metallic compound isTMA and the α carbon of R²² of the monomer unit (3) is the tertiarycarbon, setting the heating temperature at 50° C. or higher, preferably100° C. or higher likely enables R²² to decompose and allows TMA tofirmly bond to the organic film.

When the metallic compound is TMA, and the α carbon of R²² of themonomer unit (3) is the secondary carbon, setting the heatingtemperature at 80° C. or higher, preferably 100° C. or higher likelyenables R²² to decompose and allows TMA to firmly bond to the organicfilm. Moreover, when the metallic compound is TMA, and the a carbon ofR²² of the monomer unit (3) is the primary carbon, setting the heatingtemperature at 100° C. or higher, preferably 120° C. or higher likelyenables R²² to decompose and allows TMA to firmly bond to the organicfilm. An upper limit of the heating temperature in this case ispreferably set to 400° C. in terms of, for example, preventing a mainchain of the polymer of the organic film pattern 3 p from beingdecomposed.

A metallic compound that is used in a CVD method or an atomic layerdeposition (ALD) method can be used as the metallic compound without anyparticular limitation.

Examples of metals included in the metallic compound include aluminum,titanium, tungsten, vanadium, hafnium, zirconium, tantalum, molybdenum,and so on. Among these organometallic compounds or halides, ones havinga sufficiently small ligand are usable as the metallic compound.

Concretely, the usable metallic compound can include at least any one ofAlCl₃, TiCl₄, WCl₆, VCl₄, HfCl₄, ZrCl₄, TMA, and the like. TMA ispreferred in this embodiment.

According to the above, the polymer constituting the organic filmpattern 3 p is metallized to form the mask pattern 3 m formed of thecomposite film of the organic film and the metallic compound. Note thatafter bonding the metallic compound in the organic film pattern 3 p, theresultant may be subjected to oxidation treatment such as exposure to awater vapor atmosphere. For example, when TMA is used as the metalliccompound in the above, TMA becomes aluminum hydroxide or the like due tothe oxidation treatment. The oxidation treatment is performed normallyby using an oxidant such as water, ozone, or oxygen plasma. Note thatthe oxidation treatment is sometimes performed naturally by moisture inair without any special treatment.

Next, the film to be processed 2 is etched by RIE, IBE, or the likewhile using the mask pattern 3 m as a mask as illustrated in FIG. 1E, toform a patterned film to be processed 2 p. This enables to form the filmto be processed 2 p provided with a processing shape having a highaspect ratio.

After that, for example, a memory cell array is formed by using analready-known method. For example, it is assumed that a hole pattern isformed on a layered film by the above-described process. A memorystructure can be formed by embedding a block layer, a charge storagelayer, a tunnel layer, a channel layer, and a core layer in such a hole.Thereafter, only nitride films are removed in the layered film throughslits formed aside from the hole pattern having the memory structure,and conductive films are alternatively embedded. This causes a layeredfilm where insulating films (oxide films) and the conductive films arealternately layered. The conductive films in the layered film can bemade to function as word lines.

Since this pattern forming material contains the polymer having themonomer unit (3) represented by the general formula (3), the metalliccompound can be firmly bonded to the organic film obtained by using thisowing to the metallization. Then, the composite film obtained by themetallization has high etch resistance and particularly high IBEresistance. This makes it possible to obtain the mask pattern 3 m withhigh etch resistance and makes it possible to impart a processing shapehaving a high aspect ratio to the film that is to be processed by usingthis pattern forming material.

When the polymer contained in this pattern forming material is thecrosslinkable polymer including the crosslinkable monomer unit having acrosslinkable functional group at a terminal of a side chain in additionto the monomer unit (3), crosslinking the polymers makes it possible tomake that the obtained organic film insoluble to organic solvent. Thisallows to form an upper layer film such as the functional film or aprecursor film thereof by coating or dropping of the solution, or thelike. It is possible to suppress mixing of the organic film with theupper layer film or the precursor film thereof. For example, an SOC(spin on carbon) film, a TEOS (tetraethyl orthosilicate) film, a resistfilm, or the like as the upper layer film or the precursor film thereofin addition to the above-mentioned SOG film, which dramaticallyincreases flexibility of design of the multilayer mask structure.

According to this pattern forming material, the organic film can beformed by the method such as spin coating, dip coating, or vapordeposition. For example, though a carbon deposition layer obtained byusing the conventionally used CVD method requires a long time for filmformation, the organic film to be the composite film provided with highetch resistance can be formed simply in a short time according to thispattern forming material. The method where the organic film is formedinto the composite film by the metallization is also a simple andeconomical method. Note that in a case of the wet coating method such asspin coating or dip coating, the composition of the embodiment can beused.

Note that in the above-mentioned embodiment, the example of metallizingthe organic film pattern 3 p mainly in a gas phase is given, but it isnot limited thereto. The organic film pattern 3 p may be metallized in aliquid phase.

Further, in the above-mentioned embodiment, mainly, the structure havingthe organic film 3, the silicon oxide film 4, and the resist pattern 5 pis presented as the multilayer mask structure, but it is not limitedthereto. Various configurations can be employed by inserting variousfilms in addition to the above-described ones or reducing some of theabove-described films as the multilayer mask structure.

In the above-mentioned embodiment, the mask pattern 3 m is formed on thesemiconductor substrate 1, but it is not limited thereto. The maskpattern can be formed on a substrate of glass, quartz, mica, or the likein addition to the semiconductor substrate of silicon or the like.

EXAMPLES

The present invention will be explained in further detail by usingexamples below, but the present invention is not limited to theseexamples.

Examples 1 to 3

A compound where R⁵ was a hydrogen atom, and each of R²² was an ethylgroup, an isopropyl group, or an s-butyl group in the compound (1) wassynthesized according to the reaction formula (1).

Dicarboxylic acid in 5-methylbenzene-1,3-dicarboxylic acid was reactedwith thionyl chloride, and then methanol was reacted in the presence oftriethylamine to protect the carboxylic acid. After that, the methylgroup was brominated with N-bromosuccinimide (NBS), reacted bytriphenylphosphine, before a vinyl group was formed by formaldehyde inthe presence of sodium hydroxide. At the same time, deprotection of thedicarboxylic acid protected by the methyl group was performed, to obtain5-vinylbenzene-1,3-dicarboxylic acid.

The obtained 5-vinylbenzene-1,3-dicarboxylic acid was dissolved in DMF(N,N-dimethyl formaldehyde) together with N, N′-carbonyldiimidazole in asmall excess. Alcohol was reacted at room temperature in the presence of1,8-diazabicyclo[5.4.0]-7-undecen (DBU) to obtain5-vinyl-1,3-bisalkylisophthalic acid.

In Example 1, when 5-vinyl-1,3-bis(ethyl)isophthalic acid (a compoundwhere R⁵ is a hydrogen atom, and each of R²² is an ethyl group in thegeneral formula (1), hereinafter, denoted as “M(1)Et”.) was obtained,ethanol was used as the alcohol.

In Example 2, when 5-vinyl-1,3-bis(isopropyl)isophthalic acid (acompound where R⁵ is a hydrogen atom, and each of R²² is an isopropylgroup in the general formula (1), hereinafter, denoted as “M(1)iP”.) wasobtained, isopropyl alcohol was used as the alcohol.

In Example 3, when 5-vinyl-1,3-bis(s-butyl)isophthalic acid (a compoundwhere R⁵ is a hydrogen atom, and each of R²² is an s-butyl group in thegeneral formula (1), hereinafter, denoted as “M(1)sB”.) was obtained,s-butyl alcohol was used as the alcohol.

Examples 4 to 8

A compound where R¹¹ was a methyl group and each of R¹² was a methylgroup, an ethyl group, an isopropyl group, an s-butyl group, or at-butyl group in the compound (2) was synthesized according to thereaction formula (2).

In Example 4, methacrylic acid chloride was reacted withdimethyl-5-hydroxy-isophthalate in the presence of trimethylamine toobtain dimethyl methacrylate isophthalate (hereinafter, denoted as“M(2)Me”.). Diethyl methacrylate isophthalate (hereinafter, denoted as“M(2)Et”; Example 5), diisopropyl methacrylate isophthalate(hereinafter, denoted as “M(2)iP”; Example 6), di-s-butyl methacrylateisophthalate (hereinafter, denoted as “M(2)sB”; Example 7), anddi-t-butyl methacrylate isophthalate (hereinafter, denoted as “M(2)tB”;Example 8) were similarly obtained by carrying out similar reactionswith diethyl 5-hydroxy isophthalate, diisopropyl 5-hydroxy isophthalate,di-s-butyl 5-hydroxy isophthalate, and di-t-butyl 5-hydroxyisophthalate.

Examples 11 to 16

First, a polymer X constituted of only the monomer unit (3) wassynthesized according to a method described below. A composition forpattern formation was prepared by using a pattern forming materialcontaining the obtained polymer X and an organic solvent to beevaluated.

Ten mmol of the constituent monomer of the monomer unit (3) and 0.1 mmolof azobisisobutyronitrile (AIBN) as an initiator were put in a 100 ccround-bottomed flask, and approximately 5 mL of toluene was added as asolvent. After air in the flask was removed by nitrogen, polymerizationwas carried out under the temperature of 100° C. for eight hours. Afterthe reaction was completed, the flask was made open to the atmosphere toterminate the polymerization, and then a reaction solution was droppedin a large excess of methanol to purify a polymer component byreprecipitation. The obtained solid was filtered off, and the solid wasdried in a vacuum for several days to obtain the desired polymer X.Table 1 presents a relationship between an abbreviation of the polymer Xand the monomer unit (3).

TABLE 1 Polymer abbreviation Monomer unit (3) X-1 M (1) Et X-2 M (1) iPX-3 M (1) sB X-4 M (2) Et X-5 M (2) iP X-6 M (2) sB

(Preparation of Pattern Forming Material and Composition for PatternFormation)

A curing agent was not added to each of the polymers X-1 to X-6 toobtain each of pattern forming materials 1 to 6 (Examples 11 to 16). Toeach of the obtained pattern forming materials 1 to 6, PGMEA was addedso that the content of each of the pattern forming materials was 10 wt%, to prepare compositions for pattern formation.

[Evaluation]

The organic films were formed by using the compositions for patternformation including the pattern forming materials 1 to 6, and ametallization process was performed by the following method to producecomposite films. A metallization property of each organic film and etchresistance of each obtained composite film were evaluated.

(Metallization Property)

The organic films were formed on Si substrates by using the patternforming materials 1 to 6, and the organic films were each metallized byusing TMA to evaluate the metallization property.

The Si substrate after UV exposure cleaning treatment for three minuteswas used. Each composition for pattern formation was coated on the Sisubstrate by spin coating. The number of rotations was adjusted to 2000to 3500 rpm according to the kind of the polymer, and after the coating,a solvent was removed by drying to form the organic film each having athickness of approximately 300 nm. Further, 200° C. annealing wasperformed to proceed a crosslinking reaction. The obtained organicfilm-attached Si substrate was cut into 15 mm square to form a samplefor the metallization process.

The metallization was performed by an atomic layer deposition (ALD)apparatus. Concretely, the metallization was performed in an exposuremode where the sample for the metallization process was placed in theALD chamber, gas-phase TMA was introduced into the chamber at apredetermined pressure, and a valve was kept closed to maintain thepressure for a predetermined time. Initial pressure was set to 900 Pa,the temperature was set to 250° C. for X-1, X-4, and 200° C. for theother polymers, and the atmosphere was held for 600 seconds. Note thatthe pressure in the chamber gradually increased as the time elapsedbecause TMA was decomposed to generate methane. TMA was coordinated toan unshared electron pair in the polymer X or a polymer XR in theorganic film through the above-stated operation.

After exposure to TMA, vapor (H₂O) was substituted for the gas phase inthe chamber to increase the pressure to a predetermined pressure, thenthe valve was kept closed to maintain the pressure for a predeterminedtime. An initial pressure was set to 300 Pa, and the atmosphere was heldfor 200 seconds. The temperature was set the same as the temperature atthe TMA exposure. The pressure in the chamber gradually decreasedbecause H₂O was consumed or adhered to a chamber inner wall. After theholding time under the H₂O filled state elapsed, each metallized samplefor the metallization process was taken out of the chamber. By thisoperation, TMA was oxidized to form aluminum hydroxide and aluminumoxide.

Here, the ALD apparatus is used for the above-described metallizationprocess, but the above-described operation is aimed on the infiltrationof TMA into the polymer and is not aimed to deposition of an atomiclayer on the substrate, what is called atomic layer deposition (ALD).Therefore, exposure time to the metallic compound is longer, and thenumber of cycles is smaller than those of normal ALD.

(Etch Resistance)

Each of the metallized organic film-attached substrates (each of thecomposite film-attached substrates) was subjected to reactive ionetching (RIE) using O₂ gas or CF₄ gas. Film thicknesses of the compositefilm of each composite film-attached substrate before and after the RIEwere measured by using an atomic force microscope (AFM), and a filmthickness difference before and after the RIE was measured as an etchingamount to calculate an etch rate [nm/sec]. Table 2 presents the results.In Table 2, “as spun” presents an etch rate measured under the statebefore metallization, and “metallized” presents an etch rate measuredfor each metallized organic film.

(1) O₂ RIE

The O₂ RIE was performed by using CI-300L (manufactured by SAMCO Inc.)under conditions of power: 50 W, bias: 5 W, flow: 5 sccm, and pressure:3 Pa.

(2) CF₄ RIE

The CF₄ RIE was performed by using CI-300L under conditions of power: 50W, bias: 10 W, flow: 5 sccm, and pressure: 3 Pa.

The etch resistance for the O₂ RIE dramatically improves as the degreeof metallization increases. The composite film formed of a polymericmaterial having an ester bond (—C(═O)—O—) on a side chain has high etchresistance to the O₂ RIE. It is thought that the metallization likelyoccurred and the etch resistance for the O₂ RIE was increased becausethere were a lot of carbonyl groups in the component. The etchresistance for the CF₄ RIE improves as the degree of metallizationincreases.

(3) IBE

Ion beam etching (IBE) was performed for each of the metallized organicfilm-attached substrates (each of the composite film-attachedsubstrates). Film thicknesses of the composite film of each compositefilm-attached substrate before and after the IBE were measured by usingthe atomic force microscope (AFM), and a film thickness differencebefore and after the IBE was measured as an etching amount to calculatean etch rate [nm/sec].

(4) RIE Resistance Assuming Memory Holes

Conditions near RIE of memory holes of a three-dimensional memory wereassumed, and etching was performed under a mixed gas condition of C₄F₆;80 sccm, Ar; 100 sccm, O₂; 54 sccm, N₂; 50 sccm. A film thicknessdifference before and after the etching was measured as an etchingamount to calculate an etch rate [nm/sec].

TABLE 2 O₂ RIE rate CF₄ RIE rate Mixed Gas RIE rate IBE rate Polymer(nm/sec) (nm/sec) (nm/sec) (nm/sec) Example kind as spun metallized asspun metallized as spun metallized as spun metallized 11 X-1 0.2 0.030.6 0.4 0.8 0.02 0.6 0.4 12 X-2 0.2 0.02 0.6 0.2 0.8 0.02 0.6 0.3 13 X-30.3 0.02 0.6 0.2 0.8 0.01 0.6 0.3 14 X-4 0.3 0.02 0.6 0.5 0.7 0.04 0.70.4 15 X-5 0.3 0.02 0.7 0.5 0.7 0.04 0.7 0.4 16 X-6 0.3 0.02 0.7 0.3 0.70.04 0.7 0.3

Examples 21 to 26

A crosslinkable polymer X constituted of only the monomer unit (3) andthe crosslinkable monomer unit was produced. A composition for patternformation was prepared by using a pattern forming material containingthe obtained polymer X and an organic solvent to be evaluated.

(Polymerization of Crosslinkable Polymer X)

Each constituent monomer of the monomer unit (3) and each constituentmonomer of the crosslinkable monomer unit presented in Table 3 werepolymerized according to the following procedure to obtain crosslinkablepolymers X-1 to X-16 by using amounts presented in Table 3. A yield ofeach of the obtained polymers X-1 to X-16 was approximately 80 to 90%.The crosslinkable monomer unit where R was a methyl group in the monomerunit L1-1 (denoted as “L1-IM” in Table 3.) was used as the crosslinkablemonomer unit.

The constituent monomer of the monomer unit (3), the constituent monomerof the crosslinkable monomer unit, and 0.1 mmol ofazobisisobutyronitrile (AIBN) as a initiator were put into a 100 ccround-bottomed flask, and approximately 5 mL of toluene was added as asolvent. After air in the flask was removed by nitrogen, polymerizationwas carried out at 100° C. for eight hours. After the reaction wascompleted, the flask was made open to the atmosphere to terminate thepolymerization, and thereafter a reaction solution was dropped in alarge excess of methanol to purify polymer components byreprecipitation. The obtained solid was filtered off, and this solid wasdried in a vacuum for several days to obtain the desired polymer X.

TABLE 3 Monomer unit (3) Crosslinkable monomer unit Polymer MonomerInput amount Monomer Input amount number kind [mmol] kind [mmol] X-11M(1)Et 9.5 L1-1M 0.5 X-12 M(1)iP 9.5 L1-1M 0.5 X-13 M(1)sB 9.5 L1-1M 0.5X-14 M(2)Et 9.5 L1-1M 0.5 X-15 M(2)iP 9.5 L1-1M 0.5 X-16 M(2)sB 9.5L1-1M 0.5

(Preparation of Pattern Forming Material and Composition for PatternFormation)

As presented in Table 4, citric acid (denoted as “CA” in Table 4) as acuring agent was added to each of the polymers X-11 to X-16 at a ratioof 0.5 mol with respect to 1 mol of a glycidyl group in each of thepolymers X, to form each of pattern forming materials 11 to 16 (Examples21 to 26). Regarding each of the obtained pattern forming materials 11to 16, PGMEA was added so that the content of each of the patternforming materials was 10 wt %, to prepare each composition for patternformation.

[Evaluation]

The organic films were formed by using the compositions for patternformation including the pattern forming materials 11 to 16, and ametallization process was performed by a similar method as Examples 11to 16 to produce composite films. The metallization property of eachorganic film and the etch resistance of each obtained composite filmwere evaluated. Table 4 presents the results.

TABLE 4 Mixed Gas Pattern forming O₂ RIE rate CF₄ RIE rate RIE rate IBErate material (nm/sec) (nm/sec) (nm/sec) (nm/sec) Polymer Curing as asas as Example kind agent spun metallized spun metallized spun metallizedspun metallized 21 X-11 CA 0.2 0.03 0.6 0.4 0.8 0.02 0.6 0.4 22 X-12 CA0.3 0.03 0.6 0.2 0.8 0.02 0.6 0.3 23 X-13 CA 0.4 0.02 0.7 0.2 0.8 0.010.6 0.3 24 X-14 CA 0.3 0.02 0.6 0.6 0.7 0.05 0.8 0.4 25 X-15 CA 0.3 0.020.7 0.5 0.8 0.04 0.7 0.5 26 X-16 CA 0.3 0.02 0.7 0.3 0.7 0.04 0.7 0.3

As presented in Table 2 and Table 4, it is clear that the composite filmformed by using this pattern forming material has high etch resistance.In particular, it was verified that all of the composite films exhibitedhigher etch resistance after metallization compared to conventional onesunder the etching conditions using the mixed gas near the RIE process toform the memory holes of the three-dimensional memory.

A method for forming a pattern in the embodiment is added to thefollowing.

1. A method for forming a pattern, comprising:

forming an organic film on a film to be processed by using a patternforming material;

patterning the organic film, and;

forming a composite film by infiltrating a metallic compound into thepatterned organic film to obtain a mask pattern formed of the compositefilm, wherein

the pattern forming material contains a polymer including a monomer unitrepresented by a general formula (3) described below,

wherein, R²¹ is a hydrogen atom or a methyl group, each R²²independently is a hydrocarbon group having 2 to 14 carbon atoms where αcarbon is primary carbon, secondary carbon or tertiary carbon, and Q isa single bond or a hydrocarbon group having 1 to 20 carbon atoms whichmay include an oxygen atom, a nitrogen atom, or a sulfur atom betweencarbon-carbon atoms or at a bond terminal, and a halogen atom may besubstituted for the hydrogen atom.

2. The method according to clause 1, wherein

each R²² independently is an ethyl group, an n-propyl group, anisopropyl group, an n-butyl group, an isobutyl group, an s-butyl group,or a t-butyl group.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A compound represented by a general formula (1)described below,

wherein, R⁵ is a hydrogen atom or a methyl group, each R⁶ independentlyis an ethyl group, an n-propyl group, an isopropyl group, an n-butylgroup, an isobutyl group, or an s-butyl group.
 2. A compound representedby a general formula (2) described below,

wherein, R¹¹ is a hydrogen atom or a methyl group, each R¹²independently is a methyl group, an ethyl group, an n-propyl group, anisopropyl group, an n-butyl group, an isobutyl group, an s-butyl group,or a t-butyl group.
 3. A polymer including at least one of monomer unitselected from a monomer unit derived from the compound according toclaim 1 and a monomer unit derived from the compound according to claim2.
 4. A pattern forming material containing a polymer including amonomer unit represented by a general formula (3) described below,

wherein, R²¹ is a hydrogen atom or a methyl group, each R²²independently is a hydrocarbon group having 2 to 14 carbon atoms where αcarbon is primary carbon, secondary carbon or tertiary carbon, Q is asingle bond or a hydrocarbon group having 1 to 20 carbon atoms which mayinclude an oxygen atom, a nitrogen atom, or a sulfur atom betweencarbon-carbon atoms or at a bond terminal, and a halogen atom may besubstituted for the hydrogen atom, wherein, the pattern forming materialis configured to use for forming an organic film on a film to beprocessed, patterning the organic film, and then forming a compositefilm by infiltrating a metallic compound into the patterned organicfilm.
 5. The material according to claim 4, wherein each R²²independently is an ethyl group, an n-propyl group, an isopropyl group,an n-butyl group, an isobutyl group, an s-butyl group, or a t-butylgroup.
 6. A method for manufacturing of a semiconductor device,comprising: forming an organic film on a film to be processed which isprovided on a semiconductor substrate by using a pattern formingmaterial; patterning the organic film; forming a composite film byinfiltrating a metallic compound into the patterned organic film toobtain a mask pattern formed of the composite film; and processing thefilm to be processed by using the mask pattern, wherein the patternforming material contains a polymer including a monomer unit representedby a general formula (3) described below,

wherein, R²¹ is a hydrogen atom or a methyl group, each R²²independently is a hydrocarbon group having 2 to 14 carbon atoms where αcarbon is primary carbon, secondary carbon or tertiary carbon, and Q isa single bond or a hydrocarbon group having 1 to 20 carbon atoms whichmay include an oxygen atom, a nitrogen atom, or a sulfur atom betweencarbon-carbon atoms or at a bond terminal, and a halogen atom may besubstituted for the hydrogen atom.
 7. The method according to claim 6,wherein each R²² independently is an ethyl group, an n-propyl group, anisopropyl group, an n-butyl group, an isobutyl group, an s-butyl group,or a t-butyl group.